On Monday, a pair of dynamic young outfielders celebrated their birthday. Twins center fielder Byron Buxton turned 24, while Braves phenom Ronald Acuna hit the big 2-0. Both had breakout seasons in the Minors at age 19, vaulting them toward the top of prospect rankings everywhere -- Acuna this year; Buxton in 2013.
Buxton ascended to the No. 1 spot in our 2013 midseason ranking and held the top spot for the next five editions of the list, until he was supplanted by Corey Seager in our 2016 Preseason Top 100. Acuna, meanwhile, entered the list for the first time during the 2017 season and then made an astronomical leap to No. 8 in the midseason list.
Buxton, perhaps turning a corner and heading toward big league superstardom, is where Acuna wants to be, and where he'll get a chance to land next season when he makes his big league debut. That, of course, begs the question: Which player would you rather have on your team moving forward, Buxton or Acuna? MLBPipeline.com's Jim Callis and Jonathan Mayo discuss who they would choose and what figures in to the decision.

Jonathan: First, happy birthday to this dynamic pair of young outfielders. Now, to the question at hand. My initial gut reaction was Buxton. But I must admit I was really only thinking about it in terms of 2018. I think Buxton, our former perennial No. 1 prospect, really started to figure it out in Minnesota in 2017. He just started to click offensively and I believe he is still just scratching the surface. The speed has long been there and his defense made him a valuable player even when he wasn't hitting. As much as I love Acuna, I think it's too much to expect him to produce at the same rate as Buxton right out of the gate. Long term, well, that's another matter and I need to think on that a bit more. Jim, why don't we table the long-term assessment until later on in the discussion and start with just the upcoming season?
:: Buxton vs. Acuna: Tale of the tape ::
Jim: Sounds good to me. For the sake of argument, let's assume that the Braves plan on playing Acuna every day in the big leagues (which seems to be their plan but isn't guaranteed). While Acuna is arguably the best prospect in baseball -- depending on whether your definition of "prospect" includes former Japanese big leaguer Shohei Ohtani, and on whether you prefer Vladimir Guerrero Jr., as I do -- and he looked great in the Arizona Fall League, I'd still take Buxton for 2018 alone. We already know Buxton is going to be one of the most valuable defenders in the Major Leagues. He also batted .300/.347/.546 after the All-Star break last year. While he's still figuring out plate discipline, I think he'll put up better numbers in the big leagues than a 20-year-old Acuna who has played just 54 games above Double-A. Acuna still has to figure out the strike zone too, as his 144/43 K/BB ratio in 2017 will attest. Buxton struggled when he first got to the Majors and Acuna may as well. So if we're just talking about 2018, I feel pretty confident saying that Buxton will be a more productive big leaguer than Acuna.
Jonathan: OK, so we agree on that front. Buxton over Acuna in 2018. But as we both know, when we try to rank prospects, it's not about who we think will be the best rookies. It's a long-term projection. So who is going to be better over the course of their careers? That's a lot tougher to answer, but I think I'd give the edge to Buxton. Again, not slighting Acuna at all. I think he has the chance to be an All-Star. But Buxton is still so young and hasn't reached his upside potential yet, even though he's already logged close to 900 Major League at-bats. His approach, which he had completely lost when he struggled, will continue to be refined as he settles in. Look what he did in the second half: An .893 OPS with 11 homers and 35 RBIs in 207 ABs. I can easily see him duplicating that OPS over full seasons annually, and then some.
Jim: I agree with your points about Buxton -- there's still some untapped offensive potential there. If someone wants to bring up Buxton's strike-zone discipline, Acuna has the same flaw and hasn't walked as much as Buxton did in the Minors. And for all the hype about Acuna's fantastic age-19 season, Buxton put up better numbers at the same age (though Acuna got to Triple-A while Buxton got to high Class A that year). I'm really torn on this, though. While we can bank on Buxton's superb defense and he has room for offensive growth, Acuna looks like he'll be an everyday big leaguer two years before Buxton pulled it off, which is a significant difference. And if we're talking over the course of the rest of their careers, Acuna is four years younger than Buxton and theoretically should have four more seasons of Major League production in his future. So while on a season-to-season basis I think they'll be comparable in their primes, I'd take Acuna because I think he has more offensive upside and his long term should be longer.

Jonathan: I can see the greater offensive upside and yes, Acuna should get more time in, and have success in that time, than Buxton. And the case that he'll be more successful in those 20-24 seasons than Buxton is easy to make, especially since Acuna hasn't played yet. But to me, the defense is the separating factor. Acuna is a very good defender with a strong arm. But there are those who think he'll eventually slide to a corner and might not even be the best defensive center fielder in the Braves system (I'm looking at you, Cristian Pache). But really this point is all about Buxton, who's the best defensive center fielder in baseball. Period. End of story. According to Fangraphs, Buxton was third in all of baseball in defensive runs saved, behind only shortstop Andrelton Simmons and right fielder Mookie Betts. And according to Statcast™, he easily outpaces everyone in outs above average (25). The fact his WAR is as high as it is already without him reaching his offensive peak speaks volumes about how valuable his defense is.

Jim: I'm with you on Buxton's defense, which I've lauded three times during this conversation. I guess someone could nitpick him because of the injuries that dogged him in 2014 and '15, but those don't bother me at all because they weren't chronic ailments and he has been healthy the past two years. I'll still take Acuna in the long run because I think he'll establish himself in the big leagues at least a couple of years earlier than Buxton did, which is a significant marker. But it should be close, and it will be fun to see how Acuna vs. Buxton plays out over the next two decades.